Timber lock-joint.



No. 637,2!2. Patented Nov. l4, I899.

J. F. MGOUNE.

TIMBER LOOK J0 {Application filed In. 18,

(No Model.)

i W/lnesses: win en or m.C.Bux/k{ 6 v Afro/"Ry.

rm: nouns vcrzns coy. WOTOLIDIL wjsmnm. n. c

UNITED STATES Fries.

PATENT JAMES FRANKLIN MOOUNE, OF INDIANAPOLIS, INDIANA, ASSIGNOR, BY DIRECT AND MESN E ASSIGNMENTS, OF THREE-FOURTHS TO EUGENE F. HARRIS, GEORGE W. POWELL,

PLACE.

AND HARRY E. FRAZIER, .OF SAME TIMBER LOCK-JOINT.

SPEGIFICATICN forming part of Letters Patent No. 637,212, dated November 14, 18st.

Application filed March 18, 1899.

To an whom it may Concern;

Beit known that I, JAMES FRANKLIN Mo- OUNE, of Indianapolis, county of Marion, and State of Indiana, have invented a certain new and useful Timber Lock-Joint; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which like letters and figures refer to like parts.

This invention relates to a self-holding joint for wooden boards, whether used in flooring or siding, in the construction of boxes, or for any other purpose. It is of special value in flooring and siding, as the joint is of such nature that it will prevent warping or shrinking of the boards. It has all the value of the tongue-and-groove and of the ordinary rabbet joint and in addition thereto accomplishes the result mentioned above, as will appear from the following description, and especially does it make a tight, strong, durable corner-joint.

The full nature of n] yinvention will appear from the accompanying drawings and the description and claims following.

In the drawings, Figure l is a section of three boards joined by said joint. Fig. 2 is a plan of flooring where the boards are connected by said joint. Fig. 3 is a plan of a portion of a board, showing the double-faced extension. Fig. 4 is a section of two sidingboards joined by said joint.

Referring now to details, 1 is a board which is provided along its edges with lateral extensions 2, the extensions on one side being from the lower part of the board and the extensions on the other side being from the upper part of the board. The head of the extension 2 is enlarged, being thicker than at the point where the extension leaves the main body of the board. Said extension is formed by cutting away a part of the board, leaving a face 3, at right angles to the side of the board and along the edge thereof, that extends somewhat more than half through the board. Adjacent to said side face 3 of the board there is a groove 4., and at said groove the thickness of the extension is less than half the thickness of the board. The head of the extension is Serial No. 709,686. (No model.)

formed by two steps 5 and 6, leading from the groove 4. The thickness of the extension at 5 is substantially half of the thickness of the board, whereas its thickness at 6 is more than half the thickness of the board. The groove 4 and the steps form faces '7 and 8 on the sides of the steps that face inwardly toward the side face 3 of the board. The groove 4 and the steps 5 and 6 are of exactly the same width. The height of the step 5 from the groove 4- and the height of the step 6 from the step 5 are exactly equal. The angles are all sharp right angles. The end 9 of the exten= sion is parallel with the side face 3 and the faces 7 and 8 of the steps 5 and 6 and equal in length to the face 3. The extensions formed on the opposite sides of the board are exactly the reverse of each other. It is evident from this description of the extensions along the sides of the boards that when they are fitted together, as shown in Figs. 1 and 4, they will make a very tight, permanent, durable fit that holds together without additional means, al-

though additional means may be and usually I are employed. The steps 5 and 6 wedge very tightly into the groove 4 and between the surfaces 3 and 8. The side face 3 of one board is thus brought tightly against the end surface 9 of the extension on the other board. This effects a joint that will prevent warping of any board, for in order to warp a board would have to overcome the resistance of five bearing-points-namely, at A, B, O, D, and E. The same bearing-points will resist and prevent a depression of the boards at the joint. Five bearing-points oppositely located will also prevent any upward movement of the boards at the joints. In addition to these five bearing-points in case of depression and five other bearing-points to resist' an opposite movement the boards wedge into each other tightly and hold because of the large amount of contact-surface between which there is a frictional engagement that cooperates with must along one side thereof be formed somewhat differently, as shown. This may be called the corner-board 12. The part or extension then interlocking with the extension on the other board is formed on the inner side, as shown at 10, the seat to receive the extension from the other board being formed by cutting widt-hwise into the edge of the board instead of crosswise, as in all cases excepting corner-boards. This leaves an extension 11 of plain form to make the'solid corner. This corner-joint gains strength by reason of the fact that it has the same number of bearing-pointsnainely, fiveth at the other joints have to resist any modification. It also leaves the corners absolutely true, rectangular, and solid, which is very desirable in making pianos and doing fine work, because miter-joints gap and are unsightly.

One advantageous feature of this joint is in siding, where by cutting away or beveling the upper outer corners of the boards or even both of the outer corners of the boards the joints will be kept absolutely dry, as appears in Fig. at.

This joint and timber provided with it is especially useful and valuable in manufacturing freight-cars, because it-prevents warping of the roof, whereby it leaks, and shrinkage of the sides, whereby grain is lost, but holds all parts together tight. \Vhere there is a breaking of joints in the construction of roof or floor, as shown in Fig. 2, it is valuable inasmuch as it tends to hold the abutting pieces together in their proper places and prevent them frotn independently warping or twisting away from each other, whereby a crack is left or a rough surface made.

Vhat I claim as my invention, and desire to secure by Letters Patent, is

1. As an article of manufacture a board with a lateral extension along each edge from diagonally opposite corners of the board, there being a groove in each extension at its connection with the body of the board and two steps from the groove to widen the head of the extension, the angles of the extension being right angles, the dimensions of the groove and outer step being the same, and all parts of each extension being of the same form and size as the corresponding parts of the other.

2. As an article of manufacture, a board with a lateral extension along each edge from diagonally opposite corners of the board, each extension having a groove at its connection with the body of the board and two steps therefrom to form the head of the extension, the thickness of the extension at the inner step being half the thickness of the board, and its thickness at the groove and outer step being respectively less and greater than half the thickness of the board,and the dimensions of the groove and outer step being equal.

3. A timber-joint comprising two boards whose adjacent edges are similarly but reversely cut, each extension having a groove at its connection with the body of the board and two steps therefrom to form the head of the extension, the angles being all right angles, and the dimensions of the groove and outer step being the same.

4. A solid corner timber-joint comprising two boards one a corner-board that has its corner adjacent to the other board cut out to form a widthwise double-stepped rectangular groove and extension throughout its length and the other board with its inner adjacent corner cut out to form a double-stepped rectangular groove to receive the extension of the corner-board and to leave an extension of similar form to fit in the groove in the corner-board, the thickness of such extension being such as to make said board flush on its outside with the edge of the corner-board.

In witness whereof I have hereunto aflixed my signature in the presence of the witnesses herein named.

JAMES FRANKLIN MCCUNE.

Witnesses:

AMANDUS N. GRANT, R0131". D. HAWKINS. 

